An example of a surgical stapler suitable for endoscopic applications is described in U.S. Pat. No. 5,465,895, which is hereby incorporated herein by reference in its entirety. Such device comprises an endocutter that has distinct closing and firing actions. Another example of a motor driven surgical stapler is disclosed U.S. patent application Publication No. 2007/0175958, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH USER FEEDBACK SYSTEM, published Aug. 2, 2007, now U.S. Pat. No. 7,766,210, which is hereby incorporated herein by reference in its entirety. Excerpts of such Publication are presented here to detail its base functions, improvements, background, and components. At the end, additional improvements to the system are disclosed.
U.S. patent application Publication No. 2007/0175958, now U.S. Pat. No. 7,766,210, provides in part that “[a] clinician using this device is able to close the jaw members upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler with a single firing stroke, or multiple firing strokes, depending on the device. Firing the surgical stapler causes severing and stapling of the tissue. The simultaneous severing and stapling avoids complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever and staple.”
One specific advantage of being able to close upon tissue before firing is that the clinician is able to verify via an endoscope that the desired location for the cut has been achieved, including a sufficient amount of tissue has been captured between opposing jaws. Otherwise, opposing jaws may be drawn too close together, especially pinching at their distal ends, and thus not effectively forming closed staples in the severed tissue. At the other extreme, an excessive amount of clamped tissue may cause binding and an incomplete firing.
Endoscopic staplers/cutters continue to increase in complexity and function with each generation. One of the main reasons for this is the quest for lower force-to-fire (FTF) to a level that all or a great majority of surgeons can handle. One known solution to lower FTF is to use C02 or electrical motors. These devices have not faired much better than traditional hand-powered devices, but for a different reason. Surgeons typically prefer to experience proportionate force distribution to that being experienced by the end-effector in the forming the staple to assure them that the cutting/stapling cycle is complete, with the upper limit within the capabilities of most surgeons (usually around 15-30 lbs.). They also typically want to maintain control of deploying the staple and being able to stop at anytime if the forces felt in the handle of the device feel too great or for some other clinical reason. These user-feedback effects are not suitably realizable in present motor-driven endocutters. As a result, there is a general lack of acceptance by physicians of motor-drive endocutters where the cutting/stapling operation is actuated by merely pressing a button.
The foregoing discussion is intended only to illustrate some of the shortcomings present in the field of the invention at the time, and should not be taken as a disavowal of claim scope.